LinkedIn’s disturbing breach notice

Late last Wednesday (May 25), LinkedIn casually sent a note to its customers that opened with one of the least-calming phrases possible: “You may have heard reports recently about a security issue involving LinkedIn.” It continued to say, in effect, “Let us now distort and misrepresent those reports to make us sound as good as possible.”

The upshot of the notice was that LinkedIn was breached back in 2012 and that much of that stolen information has now resurfaced and is being used. From the LinkedIn notice: “We took immediate steps to invalidate the passwords of all LinkedIn accounts that we believed might be at risk. These were accounts created prior to the 2012 breach that had not reset their passwords since that breach.”

Before we delve into why this is potentially a big security problem, let’s first examine what LinkedIn, by its own admission, did. About four years ago, it was breached and knew about it. Why, in mid-2016, is LinkedIn only now invalidating those passwords? Because until now, LinkedIn made it optional for users to change their credentials.

Why in the world would LinkedIn have ignored the problem for so long? The only explanation I can think of is that LinkedIn didn’t take the breach’s implications very seriously. It is unforgiveable that LinkedIn knew that a large segment of its users were still using passwords that it knew were in the possession of cyberthieves.

The reason this is a potentially even worse situation is that we have to look at who the likely victims are and what is truly at risk.

According to that LinkedIn breach notice, there were only three pieces of information accessed by the thieves: “Member email addresses, hashed passwords, and LinkedIn member IDs (an internal identifier LinkedIn assigns to each member profile) from 2012.”

Presumably, the member ID would be useful to thieves trying to impersonate members and access nonpublic info. For example, some members include private/personal email addresses and phone numbers that can theoretically only be seen by first-level contacts. There might also be a history of searches performed or other information useful to an identity thief.

Why didn’t LinkedIn simply change all of the stolen member IDs back in 2012? That should have been within its power, and it could have cut off a wide range of fraudulent possibilities. The fact that those numbers are the same four years later is scary.

An email address on its own is a nice-to-have for identity thieves, but for most people, it is a piece of data that is very easily found elsewhere, since most people share theirs rather widely.

Clearly, the problem data point here is the passwords. This brings us back to the “who are the victims here?” question. These are people who haven’t changed their passwords in at least four years — even though there was extensive coverage back in 2012 of this breach. The big problem is that people who don’t change their passwords in these situations are likely to overlap with another group of people: those who tend to reuse their passwords.

So the thieves know that these passwords could quite easily get them into places far beyond LinkedIn, such as bank accounts, retail shopping sites and even the big enchilada for thieves: password-protection sites. What’s the most dangerous password most people have? The one that unlocks dozens of other passwords they have.

Why didn’t LinkedIn force its customers to change their passwords four years ago, as soon as it learned of the breach? That is the question that every LinkedIn customer must now insist be answered. And it has to be answered before they decide to renew.

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